The World Health Organisation (WHO) declared the outbreak of Ebola across West Africa as an international health emergency, on Friday following an emergency committee meeting in Switzerland.
"A coordinated international response is deemed essential to stop and reverse the international spread of Ebola," the WHO said in a statement, adding that the Committee concluded the conditions for a 'Public Health Emergency of International Concern (PHEIC)' had been met.
Urging all states affected by the infection to declare a state of emergency and activate national disaster protocols, the WHO called for mandatory "screening of all persons at international airports, seaports and major land crossings, for unexplained febrile illness consistent with potential Ebola infection."
"There should be no international travel of Ebola contacts or cases, unless the travel is part of an appropriate medical evacuation," the WHO added, falling short of a complete ban on international travel and trade.
The current outbreak of the Ebola began in Guinea in December 2013 and has now spread to Liberia, Nigeria and Sierra Leone. More than 930 people have been killed, including international health workers.
Nigeria on Wednesday said the outbreak was a 'national emergency', before declaring a state of emergency on Friday. Both Sierra Leone and Liberia have already declared a state of emergency as the spread and death toll of the infection rises.
Troops in Liberia and Sierra Leone have set up a blockade, blocking off areas affected by the outbreak, the BBC reports.
The infection, caused by a virus and spread by direct contact with infected blood or bodily fluids and tissues, has no known cure. The fatality rate is over 90%.
Fragile health systems, inexperience in dealing with Ebola outbreaks, mis-perceptions of the disease, and the significant mobility of those at risk of exposure to the virus, were listed by the WHO as current challenges posed by the outbreak.
"Several generations of transmission have occurred in the three capital cities of Conakry (Guinea); Monrovia (Liberia); and Freetown (Sierra Leone)and a high number of infections have been identified among health-care workers, highlighting inadequate infection control practices in many facilities," the WHO said.